1. Field of the Invention
The present invention generally relates to an improved and unique milling roll for use in a rice milling machine or rice whitening machine as a replacement for the existing milling roller in which the rice kernels are moved inwardly into the interior of the milling roll and the kernels of rice are rubbed against each other for removing the bran coatings rather than being rubbed against a screen surface.
2. Description of the Prior Art
Rice is one of the world's principal food crops and is grown in many areas having suitable soil and climate conditions. Rice kernels, when harvested, have an outside hull, underlying bran coatings and a hard, starchy kernel. While various harvesting and thrashing methods have been used, in order to increase production while maintaining labor costs at a minimum, mechanical harvesters and thrashers have been developed for harvesting rice. Various commercially available combines are employed for harvesting and thrashing rice thus producing rough rice or paddy which still has the hull in place and this rough rice is then milled by first removing the hulls and then polishing or whitening the rice kernels by removing the bran coatings. The technique of whitening or polishing rice kernels has involved the rubbing of the rice kernels between relatively moving surfaces. Rice millers initially utilized revolving bands or felt or soft leather to polish and smooth the kernels with this process effectively rubbing off bran coatings and some of the kernel starch. Subsequent rice milling machines have utilized a rotating milling roller disposed internally of a stationary screen so that the rice kernels are rubbed against the screen which abraded the bran coatings and permitted discharge of the bran coatings from the screen with the polished rice being discharged from a discharge spout. Various commercially available rice milling machines are available with one type of rice whitening machine being manufactured by Satake which is sometimes referred to as rice pearler. This type of device is disclosed in prior U.S. Pat. No. 3,179,140, issued Apr. 20, 1965. One of the problems resulting from the polishing or whitening of rice by the use of existing rice milling machines is the breakage of kernels. After the rice has been polished or whitened, sorting machines are used to separate the broken and unbroken kernels since rice is sold in accordance with grades with "head" rice consisting chiefly of perfect kernels while "second head" rice has substantial quantities of larger broken pieces with both of these grades being used as food and sold as fancy or choice rice depending on the color and the presence of weed seeds. The "screenings" or finely broken pieces of rice kernels are ground and used in flour mixes or sold as brewer's rice for use in distilling and brewing industries.